This seems like a really great kind of question to ask—“what’s the weirdness generator?”—in response to an intuition that’s important—many unrelated surprising deviations from the norm is suspicious, and probably there’s a single cause.
The strange pressures of their subterranean lifestyle, which eukaryote described somewhat, probably covers most of it. Inbreeding/isolation is probably the other half of the puzzle.
I’ll try to show how some of these traits tie in with low-oxygen and subterranean living, in those places where it wasn’t already covered.
A lot of these do bottom out to the pressures of creating a large nest, and dealing with an underground low-oxygen environment.
Eusociality and large protective communal nest-building mesh together really well, which I think fed into a lot of the items in the Richard Alexander list of predictions mentioned above (the accuracy is really impressive!).
Lack-of-hair and weird teeth seem pretty obviously developed for digging/crawling lifestyle. Acid-pain immunity has been proposed to be a consequence of having to handle an otherwise-intolerable level of lactic acid buildup (‘sore muscles’) while digging in low-oxygen zones. The strange metabolic properties (which probably feed into cancer resistance considerably) also seem to be a way to handle their lower-oxygen-availability lifestyle; endothermy can be surprisingly energy-intensive.
Really, living a low-temperature low-sugar careful-energy-usage low-ambient-cell-replication lifestyle tends to defend against cancer and improve lifespan quite a bit in general (ex: calorie restriction for mammals often extends lifespan, raising fruit flies at low temperatures can full-on double it). Molerats seem to have been under heavy pressure to biologically enforce a strict energy-usage regimen, and they take this to an incredible extreme. So you’d expect to see some cancer resistance, although it’s still crazy in terms of degree.
(I’d totally buy that they probably have some additional nutty things going for them. I think I’ve heard a theory that they have unusually-stringent cell checkpoints pre-division?)
Inbreeding and genetic isolation
No, really. It’s both a strong push towards kin-selection (a basis of eusociality if there ever was one), and an exacerbator of genetic drift. The changes might not always be anywhere near this favorable, but isolation still tilts things towards the weird, and the faster rate to saturation increases your ability to build adaptations on top of adaptations. (see also: high weirdness for species living in islands, caves).
This seems like a really great kind of question to ask—“what’s the weirdness generator?”—in response to an intuition that’s important—many unrelated surprising deviations from the norm is suspicious, and probably there’s a single cause.
The strange pressures of their subterranean lifestyle, which eukaryote described somewhat, probably covers most of it. Inbreeding/isolation is probably the other half of the puzzle.
I’ll try to show how some of these traits tie in with low-oxygen and subterranean living, in those places where it wasn’t already covered.
A lot of these do bottom out to the pressures of creating a large nest, and dealing with an underground low-oxygen environment.
Eusociality and large protective communal nest-building mesh together really well, which I think fed into a lot of the items in the Richard Alexander list of predictions mentioned above (the accuracy is really impressive!).
Lack-of-hair and weird teeth seem pretty obviously developed for digging/crawling lifestyle. Acid-pain immunity has been proposed to be a consequence of having to handle an otherwise-intolerable level of lactic acid buildup (‘sore muscles’) while digging in low-oxygen zones. The strange metabolic properties (which probably feed into cancer resistance considerably) also seem to be a way to handle their lower-oxygen-availability lifestyle; endothermy can be surprisingly energy-intensive.
Really, living a low-temperature low-sugar careful-energy-usage low-ambient-cell-replication lifestyle tends to defend against cancer and improve lifespan quite a bit in general (ex: calorie restriction for mammals often extends lifespan, raising fruit flies at low temperatures can full-on double it). Molerats seem to have been under heavy pressure to biologically enforce a strict energy-usage regimen, and they take this to an incredible extreme. So you’d expect to see some cancer resistance, although it’s still crazy in terms of degree.
(I’d totally buy that they probably have some additional nutty things going for them. I think I’ve heard a theory that they have unusually-stringent cell checkpoints pre-division?)
Inbreeding and genetic isolation
No, really. It’s both a strong push towards kin-selection (a basis of eusociality if there ever was one), and an exacerbator of genetic drift. The changes might not always be anywhere near this favorable, but isolation still tilts things towards the weird, and the faster rate to saturation increases your ability to build adaptations on top of adaptations. (see also: high weirdness for species living in islands, caves).